While the movies establish that only one timeline can exist, they also establish that it can be changed. When Doc and Marty met, Marty’s changes hadn’t happened yet. When Marty returns to 1985, the Doc he meets there has the memories of the ‘new’ events in 1955. They now have divergent memories of their time together. Just like the scene where his family is changed and the car isn’t the same wreck.

I’ve always wondered if his memories would shift to for the changes, like the picture in the past.

You're underestimating how central the theme of emotional attachments is to the franchise. Luke's journey, I suspect, parallels that of the Jedi Order in general in that as a young man, he ignored (or wasn't aware of) the order's stance, but when he experienced the pain of learning about his father, he overreacted and took on a more dogmatic stance.

The limited history of Tarre Vizsla suggests that the Order may not have always been so dogmatic. If the Order of the time accepted how Viszla balanced both Jedi and Mandelorian philosophies - or at least didn't actively reject it - something must have changed between that era (Old Republic? Earlier?) and the time of the Galactic Republic.

My guess is that the Sith Wars pushed the order into hardline thinking - eschewing balance for dogmatism.

If the storyline of Din Djarin and Grogu continues, an obvious endpoint would be for Grogu to be the next Tarre Vizsla, restoring both Mandelor and the Jedi by returning balance to their ways of thinking.